CARLTON star Tom De Koning will miss the remainder of the home and away season with a fractured foot, while he also has a collapsed lung, in a significant setback for the club's top-two hopes.
De Koning underwent scans on Monday morning that discovered a fractured foot, though the Blues remain hopeful he will make his return before the club's September campaign.
The ruck hurt his foot in the opening stages of Sunday's win over North Melbourne, but returned to the field after an extended period on the sidelines and played out the contest.
He has also been hospitalised with a collapsed lung, sustained late in the game, following an otherwise innocuous behind-play incident with Kangaroos ruck Tristan Xerri.
Carlton had earlier cleared star forward Harry McKay of a concussion after follow-up tests on Monday morning, but the club had been sweating over the fitness of De Koning and Blake Acres ahead of Friday night's clash with Port Adelaide.
McKay copped a knock to the nose in the third quarter of the side's win over North Melbourne on Sunday night, but passed a head injury assessment (HIA) during the game and played out the match.
Further tests in the 24 hours after the incident discovered no issues, with McKay cleared of any concussion problems and set to be made available for the side's important fixture against the Power at Marvel Stadium.
However, the AFL has sent Carlton – as well as Adelaide and Brisbane – a 'please explain' notice following incidents over the weekend in relation to "the management of their respective concussion management protocols".
The Blues were sent one regarding McKay, while the Crows were flagged about captain Jordan Dawson and the Lions were noted for an incident involving co-captain Harris Andrews.
The Blues have also sent Acres in for scans on Monday, though, after he also left a bruising encounter against the Kangas with a foot problem of his own that forced him to be substituted out of the game.
Carlton has replacement options for both players, with ruck Marc Pittonet finishing with 17 disposals, 25 hitouts and eight clearances in the VFL on Sunday and young wing Jaxon Binns racking up 47 disposals and kicking three goals.
The Blues are confident star midfielder Sam Walsh will be available, having left the game feeling discomfort in his back following a heavy knock in the dying stages of the win over the Kangaroos.
Carlton coach Michael Voss said afterwards the issue was a "direct knock" and separate to the back injury that has troubled Walsh in the past and kept him sidelined for the first four games of this season.
Key defender Sam Durdin hurt his calf in the opening stages of the game and was clearly hobbled by the blow, but played out the match, while Matt Kennedy also came back onto the field after a knock to his foot and should be OK for this weekend.
Carlton expects defender Mitch McGovern to return ahead of this Friday night's clash with Port Adelaide, having missed time with a hip flexor problem, while Caleb Marchbank is also likely to be available having recovered from illness.
Running defender Jordan Boyd is also likely to return following a shin problem, having been pulled from Sunday's game after failing to make it through last Friday's main session.
Jack Martin also played increased minutes in the reserves on Sunday, winning 17 disposals, and could add to his solitary appearance of the season should he earn a recall following hamstring and calf issues.
Carlton, along with the Western Bulldogs, were one of only two teams to be handed a five-day break in the AFL's second fixture release for rounds 16-23 and take on Port Adelaide off the shorter turnaround this weekend.
Blues players have Monday off, following Sunday's twilight fixture against North Melbourne, with the hobbled players likely to face fitness tests in Wednesday's only main training session of the week.